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LESSON

1.1

98-366 Networking Fundamentals

Understand the Concepts of the Internet, Intranet, and Extranet

LESSON

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98-366 Networking Fundamentals

Lesson Overview In this lesson, you will learn about: 

The Internet



Intranets



Extranets



VPN



Security Zones



Firewalls

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98-366 Networking Fundamentals

Anticipatory Set: 1.

Discuss how the Internet was created by the US Department of Defense, when the project started, and the impact it has had on society

2.

Discuss the uses of a virtual private network (VPN) and relate sample situations where it is used

LESSON

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98-366 Networking Fundamentals 

In 1962 ARPA opened a computer research program and appointed an MIT scientist named John Licklider to lead it. He had just published his first memorandum on the "Galactic Network" concept ... a futuristic vision where computers would be networked together and would be accessible to everyone.



In October 1969, Internet messaging programs (IMPs) were installed in computers at both UCLA and Stanford. UCLA students would 'login' to Stanford's computer, access its databases and try to send data.

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98-366 Networking Fundamentals



The experiment was successful and the fledgling network had come into being



By December 1969 ARPANET comprised four host computers with the addition of research centers in Santa Barbara and Utah



This was the beginning of the Internet

LESSON

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98-366 Networking Fundamentals 

Access to the Internet was now available and it was hypertext document servers and Mosaic, the graphical browser, that became the killer application that made the Internet popular and useful to the general public



This worldwide computer network allows people to communicate and exchange information



The Internet is not owned by any particular company or person

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98-366 Networking Fundamentals

Intranet 

A private network based on Internet protocols such as TCP/IP but designed for information management within a company or organization



One of the key advantages of an intranet is the broad availability and use of software applications unique to the needs of a corporation



It is also a computer network and includes some of the same technologies as the Internet

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98-366 Networking Fundamentals 

Intranet uses include providing access to software applications; document distribution; software distribution; access to databases; and training



An intranet is so named because it looks like a World Wide Web site and is based on the same technologies, yet is strictly internal and confidential to the organization and is not connected to the Internet proper



Some intranets also offer access to the Internet, but such connections are directed through a firewall that protects the internal network from the external Web

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98-366 Networking Fundamentals

Extranet 

An extension of some combination of corporate, public, and private intranet using World Wide Web technology to facilitate communication with the corporation’s suppliers, customers, and associates



An extranet allows customers, suppliers, and business partners to gain limited access to a company’s intranet in order to enhance the speed and efficiency of their business relationship

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98-366 Networking Fundamentals

VPN 

Virtual private network are nodes (nodes are a connection point, either a redistribution point or a communication endpoint (some terminal equipment) on a public network



They communicate among themselves using encryption so that their messages are safe from being intercepted by unauthorized users



VPNs operate as if the nodes were connected by private lines. An example would be teachers at home needing limited access to the school district’s intranet would be given VPN software for their personal laptop

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Security Zone 

Business/organization's need for physical and logical boundaries for accessing, controlling, and securing information throughout an organization's network



The security zone contains hidden settings for how Microsoft Windows and Internet Explorer manage unsigned controls



Security changes daily. A must to keep aware of the updates. Check the webcasts where leading security and privacy experts in field discuss the issues.



Microsoft has webcasts covering Security Bulletins, Security Development Lifecycle, Security Intelligence Report, Security Tools, and more

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98-366 Networking Fundamentals

Firewall 

A computer system or network firewall is designed to permit authorized communications while blocking unauthorized access



The device is configured to permit or deny computer applications based upon a set of rules and other criteria



Firewalls are technological barriers designed to prevent unauthorized or unwanted communications between computer networks or hosts

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98-366 Networking Fundamentals

Discuss how the business would achieve creating security zones through the use of firewalls and VPNs for their intranet and extranets.

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Class Activity Student Activity 1.1: Comparing Internet, Intranet, Extranet Discuss in groups of three how our subject applies: 1. As an example use the DMV (Department of Motor Vehicles): 

Us as customers (driver’s license renewal & vehicle registration renewal) 



Highway Patrol as suppliers (vehicle ticket information) & as business partners (they request current vehicle registration information) 



DMV extranet & their own intranet

Smog check stations as suppliers (they provide smog certificates direct to DMV) 



Internet

VPN to DMV extranet

Auto dealers as business partners (new car registration) 

VPN to DMV extranet & their own intranet

2. Think and list examples of businesses that would use the same technology

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98-366 Networking Fundamentals

Lesson Review 

Work in small groups (3-4 students) to complete the network design activity from Networking Fundamentals Student Activity NetFund_SA_1.1_1 and Student Activity NetFund_SA_1.1_2



If time permits, informally present group designs to the class. Discuss the different designs created.

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Understand the Local Area Networks (LANs)

LESSON

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98-366 Networking Fundamentals

Lesson Overview In this lesson, you will learn about: 

LANs



Perimeter networks



Addressing



Local loopback IPs



An Internet collection

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98-366 Networking Fundamentals

Anticipatory Set: Class Activity 

Two students draw a slip of paper from the box. Arrange yourselves in order at the front of the room. Two more students select numbers and add to the network forming.



The student with number 1: Tell a “secret” to number 2. Continue to pass information from one student to the next until the message reaches the end of the network.



When the last person receives the message, repeat it to the class.



Describe how this process is similar and different to a computer passing information throughout a network.

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98-366 Networking Fundamentals

Just as people network and talk to each other and spread information, computers can network and talk to each other and share information.

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LANs - Local Area Networks 

Computer networks ranging in size from two computers in a home to a few computers in a single office to hundreds or even thousands of devices spread across several buildings.



They function to link computers together and provide shared access to printers, file servers, and other services.

LESSON

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98-366 Networking Fundamentals 

A group of computers and other devices dispersed over a relatively limited area and connected by a communications link that enables any device to interact with any other on the network.



LANs commonly include PCs and shared resources such as laser printers and large hard disks.



The devices on a LAN are known as nodes (individual pieces of equipment.) o

Nodes are connected by wireless and by cables and through which messages are transmitted

LESSON

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98-366 Networking Fundamentals 

LANs in turn may be plugged into larger networks, such as larger LANs or wide area networks (WANs), connecting many computers within an organization to each other and/or to the Internet.



The physical media that connect devices, interfaces on the individual devices that connect to the media, protocols that transmit data across the network, and software that negotiates, interprets, and administers the network and its services are all a part of the LAN.

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98-366 Networking Fundamentals

Perimeter Networks 

A perimeter network is a specialized network. Usually a physical subnet outside of the main firewall allowing a business to expose their services to the Internet.

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98-366 Networking Fundamentals

Addresses 

A unique identifier is assigned to each node on a network.



A computing address defines a range of discrete addresses:



o

each of which may correspond to a physical or virtual memory register

o

a network host

o

peripheral device, disk sector, or other physical entity.

Just as people have addresses, computer memory and networks have addresses.

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98-366 Networking Fundamentals

Reserved address ranges for local use 

Address ranges are reserved by IANA for private intranets, and not routable to the Internet.

The Internet Assigned Numbers Authority (IANA) 

Allocates ranges of numbers to various registries in order to enable them to each manage their particular address space.

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98-366 Networking Fundamentals

Local Loopback IPs 

127.0.0.1 is the loopback address in IP



Loopback is a test mechanism of network adapters. Messages sent to 127.0.0.1 do not get delivered to the network.



Instead, the adapter intercepts all loopback messages and returns them to the sending application.



IP applications often use this feature to test the behavior of their network interface.

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98-366 Networking Fundamentals

An Internet Connection Sharing 

ICS is a collection of technologies that work together to enable multiple devices on a private network to share a single Internet connection.



Microsoft uses the class C reserved IP range for implementing a SOHO (small office/home office) network—where one computer shares its Internet connection with other computers—similar to Microsoft's printer sharing noted in the video.

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98-366 Networking Fundamentals

Lesson Review Complete this review activity on the same paper with the flow chart you used for the applied learning. 1.

Summarize a local area network

2.

Add any questions you have about the lesson

Turn in this paper as your “ticket out the door”

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98-366 Networking Fundamentals

Class Activity



Student activity 1.2_A: Local Area Network Components.



View the video shown on the next slide.



Using form SA 1.2_A label the components of the LAN created in the video.

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Understand VLANs, Wired LANs, and Wireless LANs

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Lesson Overview In this lesson, you will review: 

Wired local area networks



Wireless local area networks



Virtual local area networks (VLANs)

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98-366 Networking Fundamentals

Anticipatory Set 

Explain why wireless networks are so popular, especially in homes



Describe the elements that make up a wireless network



What is the opposite of a wireless network?

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98-366 Networking Fundamentals

LAN 

A local area network (LAN) is a single broadcast domain. This means the broadcast will be received by every other user on the LAN if a user broadcasts information on his/her LAN. Broadcasts are prevented from leaving a LAN by using a router.

Wired LAN 

An electronic circuit or hardware grouping in which the configuration is determined by the physical interconnection of the components

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98-366 Networking Fundamentals

Wireless LAN 

Communications that take place without the use of interconnecting wires or cables, such as by radio, microwave, or infrared light



Wireless networks can be installed: o

o

Peer-to-peer “Ad hoc” mode—wireless devices can communicate with each other "Infrastructure" mode—allows wireless devices to communicate with a central node that can communicate with wired nodes on that LAN

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98-366 Networking Fundamentals

Sample example of a wireless LAN design:

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Wired LANs: Advantages Most wired LANs are built with inexpensive hardware: 1.

Network adapter

2.

Ethernet cables

3.

Hubs

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98-366 Networking Fundamentals

Advantages 

Wired LANs provide superior speed and performance

Disadvantages 

Difficult to run cables under the floor or through walls especially when computers sit in different rooms



Require central devices like hubs or routers to accommodate more computers, which can be expensive



Generally it costs less than wireless equipment for the equivalent wired Ethernet products

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Wireless LANS: Advantages 

Easy access to the Internet in public places



Less expensive to install and maintain



Alleviates the need to run wiring through buildings

Disadvantages 

The data transfer rate will decrease as computers are added



Lower wireless bandwidth means video streaming will be slow



Security is more difficult to guarantee and requires configuration

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98-366 Networking Fundamentals

Application of LANs 

Home and small business computer networks can be built using either wired or wireless technology



Large companies are trying to move toward wireless but there are more challenges, especially with security



Wired Ethernet has been the traditional choice in homes, but Wi-Fi wireless technologies are quickly replacing wired LANs

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98-366 Networking Fundamentals

VLAN 

A virtual LAN, known as a VLAN, is a group of hosts with a common set of requirements that communicate regardless of their physical location



Sometimes called a “logical network”



Has the same attributes as a physical LAN, but allows for end stations to be grouped together even if they are not located on the same network switch



Network reconfiguration can be done through software

LESSON

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98-366 Networking Fundamentals 

The VLAN controller can change or add workstations and manage load balancing and bandwidth allocation more easily than with a physical picture of the LAN



Network management software keeps track of relating the virtual picture of the local area network with the actual physical picture

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98-366 Networking Fundamentals

Lesson Review 1.

2.

Why is a VLAN sometimes referred to as a “logical network”? List the advantages and disadvantages for a wired network and a wireless network. Give examples of a typical uses for each.

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Understand Wide Area Networks (WANs)

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98-366 Networking Fundamentals

Lesson Overview In this lesson, you will review: 

Dial-up



Integrated services digital networks (ISDN)



Leased lines



Virtual private networks (VPN)



Wide area networks (WAN)

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98-366 Networking Fundamentals

Anticipatory Set Apply what you have learned about LANs to this lesson. 1.

What have you learned in the past that will help you to understand WANs?

2.

Discuss with your neighbor how you can apply learning from past experience to this new topic of WANs.

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Dial-up Connections 

A connection that uses the public switched telephone networks rather than a dedicated circuit or some other type of private network.



This is often referred to as plain old telephone service/public switched telephone service (POTS/PSTN).



Remote server access provides two different types of remote access connectivity: o

Dial-up remote access

o

Virtual private network (VPN) remote access

LESSON

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98-366 Networking Fundamentals 

With dial-up remote access, a remote access client uses the telecommunications infrastructure to create a temporary physical circuit or a virtual circuit to a port on a remote access server.



After the physical or virtual circuit is created, the rest of the connection parameters can be negotiated.

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ISDN - Integrated Services Digital Network 

A high-speed digital communications network evolving from existing telephone services.



Designed to replace the current telephone network



An ISDN communication channel carries voice, circuit, or packet conversations. The B channel is the fundamental component of ISDN interfaces. It carries 64,000 bits per second in either direction.



The most common kind of ISDN interface available in the United States is BRI, which contains two B channels, each with 64-kbps capacity, and a single D channel (16-kbps) that is used for signaling and call progress messages.

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Leased Lines 

A communications channel that permanently connects two or more locations.



Leased lines are private or dedicated lines, rather than public ones. Also called dedicated connection and private line.



A leased line is a dedicated telephone line rented from the phone company. It provides a 24 hour dedicated connection between two points.



Leased lines can be almost any speed but are typically 2 Mbps. Higher speed lines are more expensive.

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VPN - Virtual Private Network 

Computer devices (nodes) on a public network that communicate among themselves using encryption technology so that their messages are as safe from being intercepted and understood by unauthorized users as if the nodes were connected by private lines.



VPN client uses an IP (Internet protocol) internetwork to create a virtual point-to-point connection with a remote access server acting as the VPN server.



A server-based computer can be a remote-access server so that other users can connect to it by using VPN, and then access shared files on your local drives or on your network.

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Basic VPN Requirements 

User Permission. Enable a user to access the VPN



IP Configuration. The VPN server should have a static IP address and assign the arrange of IP addresses to VPN clients.



The VPN server must also be configured with DNS (Domain Name System) and WINS (Windows Internet Name Service) server addresses to assign to the VPN client during the connection



Data Encryption. Data carried on the public network should be rendered unreadable to unauthorized clients on the network

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Basic VPN Requirements (continued) 

The TCP/IP (transmission control protocol/Internet protocol) is a common protocol used in public networks



Firewall Ports. VPN server behind the firewall requires port implementation



Interface(s) for VPN server. If using a router, only one NIC (network interface controller) is needed. If the network doesn't have a router or the VPN is also a gateway, the computer must have at least two interfaces, one connecting to the Internet and another connecting to the LAN.



One interface for VPN client. The interface can be a dial-in modem, or a dedicated connection to the Internet

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WAN - Wide Area Network 

Geographically widespread network



Relies on communications capabilities to link the various network segments



Can consist of a number of linked LANs (local area networks) or it can be one large network



Used to connect LANs and other types of networks together, so that users and computers in one location can communicate with users and computers in other locations

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LAN to a Wide Area Network

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Lesson Review 1.

Compare networks and discuss the relationship of a wide area network to a local area network and a virtual private network.

2.

How do leased lines, dial-up, and ISDN relate to wide area networks?

3.

Discuss your answers with two other students and refine your thoughts. Share your answers with the class.

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Understanding Wide Area Networks

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Lesson Overview In this lesson, you will learn about: 

T1



T3



E1



E3



DSL



Cable and its characteristics (speed, availability)

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98-366 Networking Fundamentals

Anticipatory Set 

Pass sample cables around the class. Share with another student and answer if and where you have seen these cables before.



Review how a LAN would be designed for the classroom. How do you imagine the design for a WAN is different?

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T1 

A high-speed communications line that can handle digital communications and Internet access at the rate 1.544 Mbps (megabits per second).



This high-bandwidth telephone line can also transmit text and images.



Speed is attained through multiplexing 24 separate 64 Kbps channels into a single data stream.



Commonly used by larger organizations for Internet connectivity.

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T3 

A T-carrier that can handle 44.736 Mbps (megabits per second) or 672 voice channels.

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E1 

A 2.048 Mbps point-to-point dedicated, digital circuit provided by the telephone companies in Europe.



The European counterpart of the North American T1 line.



E1 and T1 lines can be interconnected for international use.



Uses two wire pairs (one for transmit, one for receive) and time division multiplexing (TDM) to interleave 32 64Kbps voice or data channels.

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E3 

A carrier service with capacity for 34.368 Mbps



The E3 lines is the European counterpart to the US T3



Europe has a counterpart for every T-carrier leased line capability



A speed capacity of 34.368 Mbps o



Interesting since E1 is faster than a T1 and E2 is faster than a T2 but E3 is slower than a T3

E2 through E5 lines provide multiple E1 channels

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DSL - Digital Subscriber Line 

Provides high-speed transmissions over standard copper telephone wiring



The data throughput of consumer DSL services ranges from 384 Kbps to 20 Mbps in the direction to the customer o



Depends upon technology, line conditions, and service-level.

The data throughput in the reverse direction—from customer to the service provider—is lower o

Asymmetric digital subscriber line (ADSL) is the most common DSL service provided but still with limited availability

o

Symmetric digital subscriber line (SDSL) provides equal speed in both directions

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Cable Internet Access through CATV 

Has become a viable alternative and many cable companies are offering both a home and a businessclass connection.

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Reflection – Class Activity 1.

With a partner discuss the similarities and differences between T1, T3, E1, E3.

2.

Create a table showing the similarities and differences.

3.

Indentify North American (T-carrier) and European (Ecarrier).

4.

Include such items as number of lines, number of channels, & max data rate.

5.

Discuss why such ranges exist and describe situations that would require the various options.

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Understand Wireless Networking

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Lesson Overview In this lesson, you will learn about:

Wireless networking  Wireless networking standards and their characteristics  802.11a, b, g, n including different GHz ranges  Types of network security oWPA oWEP o802.1X  Point-to-point (P2P) wireless  Wireless bridging  Gigahertz

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Anticipatory Set 1.

Make a list of all the wireless devices they have seen, used, or are familiar with. Answer the following questions relating to the devices in the list.

a.

How do they transmit and communicate with other devices?

b.

It is likely that there are many wireless devices in the same room or area. How are they able to not interfere with each other ? Or do they interfere with each other?

2.

Discuss the uses and security issues of these items

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Wireless Telecommunications 

Computer networks created without wires such as a local area network (LAN)



The telecommunications network employ interconnections between nodes implemented without the use of wires



Wireless telecommunications networks are accomplished with some type of remote information transmission system

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Wireless Telecommunications (continued) 

This implementation takes place at the physical level or "layer" of the network where the waves are like radio waves.



Waveform refers to the shape and form of a carrier signal such as a radio wave. A wave is a disturbance that travels through space and time moving in a solid, liquid, or gaseous medium.



This carrier signal uses the same basic protocol as a modulating signal.

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Electromagnetic Waves 

The wave, or "disturbance," is invisible and is called the force field.



Without these charged particles, there can be no electric force fields and thus no electromagnetic waves.



Examples include light, microwaves, X-rays, and TV and radio transmissions are all kinds of electromagnetic waves.



Negative electrons and positive protons charges cause each other to move.



Positive charge exerts an attractive force on electrons—an electric force.



The velocity makes no difference, the pull or force depends only upon where you put it.



Electronic devices make use of the range of the electromagnetic spectrum.

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Wireless 

Describes communications in which electromagnetic waves or RF carry a signal over the entire communication path.



The frequencies that are available for use for communication are a public resource and are regulated by the Federal Communications Commission in the U.S.

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Electronic Modulation 

The process of varying one or more properties of a high-frequency periodic waveform.



In wireless we first take a signal, like a telephone conversation, and then impress it on a constant radio wave called a carrier.



It modulates a constant frequency in the radio range, which we can't hear.



Modulation makes voice band and radio band frequencies work together.



Different modulation techniques, such as AM and FM, are different ways to shape or form electromagnetic radio waves.

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Electronic Modulation (continued) 

Wireless network technologies are used in phones, laptop computers, automobiles, and public transportation.



High-speed wireless Internet connection services designed to be used from arbitrary locations refers to "mobile broadband.”



Wi-Fi hotspots provides connectivity over a limited radius around fixed wireless access points.



The data rate of a computer network connection is measured in units of bits per second (bps).



One Mbps equals one megabyte per second.



Network equipment makers rate their products using related, larger units of Kbps, Mbps, and Gbps.



Network outages happen due to limits of the service provider coverage area or obstructions from geography, or even inside larger buildings.

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Institute of Electrical and Electronics Engineers (IEEE) 

Creates standards to ensure compatibility.



The IEEE created the 802 project to develop the standards which are used today. There have been many changes and additions.



IEEE 802 standards define only certain technologies.



Most important IEEE 802 standards is the 802.11, wireless networks—it defines standards for wireless LAN communication.



IEEE 802.11 is a set of standards carrying out wireless local area network (WLAN) computer communication in the 2.4, 3.6 and 5 GHz frequency bands.



The base current version of the standard is IEEE 802.11-2007. They are created and maintained by the IEEE LAN/MAN Standards Committee (IEEE 802).

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Popular Protocols Defined by the 802.11b and 802.11g 

802.11-1997 was the first wireless networking standard.



802.11b was the first widely accepted one, followed by



802.11g and then by 802.11n.



802.11n is a new multistreaming modulation technique.



The 802.11 family includes over-the-air modulation, which means to change or vary.

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98-366 Networking Fundamentals 

802.11b and 802.11g use the 2.4 GHz ISM band (industrial, scientific and medical), operating in the United States under Part 15 of the US Federal Communications Commission Rules and Regulations.



Gigahertz is a measure of frequency.



Frequency (temporal frequency ) is the number of occurrences of a repeating event per unit time.



The duration of one cycle in a repeating event, so the period is the reciprocal of the frequency.



Because of this choice of frequency band, 802.11b and g equipment may occasionally suffer interference from microwaves , cordless telephones and Bluetooth devices.

LESSON

1.1

98-366 Networking Fundamentals 

Both 802.11 and Bluetooth control their interference by using spread spectrum modulation.



Bluetooth uses a frequency hopping signaling method, while 802.11b and 802.11g use the direct sequence spread spectrum signaling and orthogonal frequency division multiplexing methods, respectively.



802.11a uses the 5 GHz U-NII (Unlicensed National Information Infrastructure) band, which offers at least 19 non-overlapping channels rather than the 3 offered in the 2.4 GHz ISM frequency band.



Depending on the environment, channels may have better or worse performance with higher or lower frequencies.

LESSON

1.1

98-366 Networking Fundamentals

WEP and WPA 

Wireless security protocols widely used by wireless networking devices



WEP—Wired Equivalent Privacy or Weak Encryption Protocol o



Designed to provide equivalent level of security as a wired network

WPA—Wi-Fi Protected Access (WPA and WPA2) o

A certification program to designate compliance with the security protocol to secure wireless computer networks

o

Implements the majority of the IEEE 802.11i standard



The Wi-Fi Alliance intended WPA as an intermediate measure to take the place of WEP pending the preparation of 802.11i



IEEE 802.11 wireless networks are NOT secured by WEP as it is easily broken

LESSON

1.1

98-366 Networking Fundamentals

Wireless Security 

Wireless network messages are more susceptible to eavesdropping than wired networks.



A WEP key uses a passphrase – a security code that is produced using this protocol that allows computers to hide the contents of the messages from intruders and exchange coded messages.



WPA-PSK (Pre-Shared Key) mode provides strong encryption protection without the enterprise authentication server and is the easiest way to deploy WPA to home wireless network using a passphrase.



WPA uses Temporal Key Integrity Protocol (TKIP) to produce unique encryption keys and automatic rekey each wireless clients from passphrase and network SSID.

LESSON

1.1

98-366 Networking Fundamentals

Wireless Bridging A bridge is used to connect two network segments.

LESSON

1.1

98-366 Networking Fundamentals

Bridging 

A forwarding technique used in packet-switched computer networks.



Can be done wired or wireless and used only in LANs.



Bridging depends on flooding and examination of source addresses in received packet headers to locate unknown devices.



A network bridge connects multiple network segments at the data link layer (Layer 2) of the (OSI) Open System Interconnection model.



A switch is a bridge with numerous ports. Switch or Layer 2 switch is often used interchangeably with bridge.

LESSON

1.1

98-366 Networking Fundamentals

Bridging (continued) 

Another form of bridging, source route bridging, was developed for token ring networks.



The main purpose of wireless bridging is to connect a wired Ethernet network segment to a wireless Ethernet network segment .



This is most commonly found in a home wireless router that has a built-in multiport switch for wired devices, and a wireless networking WAN connection for DSL or cable for Internet access.

LESSON

1.1

98-366 Networking Fundamentals

Point-to-Point Protocol (PPP) 

A data link protocol commonly used to establish a direct connection between two networking nodes



Provides compression, transmission encryption privacy, and connection authentication



Used over many types of physical networks including serial cable, phone line, trunk line, cellular telephone, specialized radio links, and fiber optic links such as links



Internet service providers (ISPs) use PPP for customers’ dial-up access.



Internet service providers (ISPs) use two encapsulated forms of PPP to connect Digital Subscriber Line (DSL) Internet service.  Point-to-Point Protocol over Ethernet (PPPoE)  Point-to-Point Protocol over ATM (PPPoA)

LESSON

1.1

98-366 Networking Fundamentals

Lesson Review 

Compare WEP and WPA by creating a list of the advantages and disadvantages of each



Discuss the various wireless transmission methods

LESSON

1.5 1

98-366 98-366Networking NetworkingFundamentals Fundamentals

Understand Network Topologies and Access Methods

LESSON

1.1

98-366 Networking Fundamentals

Lesson Overview In this lesson, you will learn about: Network

topologies and access methods

Star

Mesh Bus Ring

LESSON

1.1

98-366 Networking Fundamentals

Anticipatory Set We previously discussed networks such as local area networks and this leads to the topic of topology—how the network is structured. 1.

Draw a network that includes: 3 computers , 2 desktops and a laptop, and a network printer.

2.

Be prepared to show your drawing and tell what network topology is being used.

LESSON

1.1

98-366 Networking Fundamentals

Class Activity Use the mind map during the PowerPoint presentation to record information about the different types of network topologies. Be sure to include information about which topology types are appropriate for various situations.

LESSON

1.1

98-366 Networking Fundamentals

Network Topologies 

The interconnection of the various elements (links, nodes, etc.) of computer equipment



Network Topologies can be physical or logical



Topology is the virtual shape or structure of a network, which does not need to correspond to the actual physical design of the devices on the computer network.



The physical design of a network including the devices, location, and cable installation is known as physical topology.



How data actually transfer in a network, as opposed to its physical design, is the logical topology, also called signal topology.

LESSON

1.1

98-366 Networking Fundamentals

Compare the logical and physical topology of the star If a hub is used, then the topology is a physical star and a logical bus. If switch is used, then the topology is a physical star and a logical star.

If IBM MAU is used, then the topology is a physical star and a logical ring.

LESSON

1.1

98-366 Networking Fundamentals

Star Network 

The topology structure of a star network consists of one central switch, hub or computer, which acts as a conduit to transmit messages.



The hub and leaf nodes, and the transmission lines between them, form a graph with the topology of a star.



An active star network has an active central node that usually has the means to prevent echo-related problems.

LESSON

1.1

98-366 Networking Fundamentals 

By connecting all of the systems to a central node, the star topology reduces the chance of network failure.



The central hub rebroadcasts all transmissions received from any peripheral node to all peripheral nodes on the network when applied to a bus-based network.



All peripheral nodes may thus communicate with all others by transmitting to, and receiving from, the central node only.



Isolation of a peripheral node from all others occurs when there is a failure of a transmission, but the rest of the systems will be unaffected.



Each node (file servers, workstations, and peripherals) is designed to be connected directly to a central network hub, switch, or concentrator.

LESSON

1.1

98-366 Networking Fundamentals 

Data on a star network passes through the hub, switch, or concentrator before continuing to its destination.



The functions of the network are controlled and managed by the hub, switch, or concentrator, and it acts as a repeater.



The twisted pair cable is the most often used although it can be used with coaxial cable or optical fiber cable.

LESSON

1.1

98-366 Networking Fundamentals

Mesh Networks 

Each node in the network acts as an independent router.



A mesh network whose nodes are all connected to each other is a fully connected network.



The component parts connect to each other via multiple hops.



Is self-healing and can still operate when one node breaks down or a connection goes bad



Considered more reliable than other networks



Mobile ad hoc networks (MANET) must deal with the problems of the mobility of the nodes. Mesh networks do not have this problem but they are closely related with the MANET network.

LESSON

1.1

98-366 Networking Fundamentals 

Originally developed for military applications



Wireless networks are typical of mesh architectures.



The mesh network can support multiple functions such as client access, backhaul service, and scanning in mobile applications.



Increased power has enabled the mesh nodes to become more modular.



One node or device can contain multiple radio cards or modules, allowing the nodes to be customized to handle a unique set of functions and frequency bands.



Game theory methods that analyze strategies for the allocation of resources and routing of packets have aided mesh networks.

LESSON

1.1

98-366 Networking Fundamentals

Ring Network 

Data travels from node to node, with each node along the way handling every packet.



It forms a single continuous pathway for signals through each node.



May be disrupted by the failure of a single link



A node failure or cable break might isolate every node attached to the ring.



Each machine or computer has a unique address that is used for identification purposes.



Only one machine can transmit on the network at a time.

LESSON

1.1

98-366 Networking Fundamentals 

Even though computers on a home network can be arranged in a circle shape, it does not mean that it presents a ring topology.



By sending data on a counter clockwise ring FDDI (fiber distributed data interface) networks circumvent a node failure or cable break.



802.5 networks, also known as Token Ring networks, avoid the weakness of a ring topology altogether. o



They actually use a star topology at the physical layer and a multistation access unit (MAU) to imitate a ring at the data-link layer.

The signal can be boosted or repeated as the computers connected to the ring act to strengthen the signals that transverse the network.

LESSON

1.1

98-366 Networking Fundamentals

Bus Network 

A shared communications line



A common backbone to connect all devices that operates and functions as a shared communication medium



A single cable that devices attach or tap into with an interface connector



Communicates by sending a broadcast message onto the wire for all other devices to see, but only the intended recipient actually accepts and processes the message.



Devices on the bus must first determine that no other device is sending a packet on the cable before any device can send a packet.

LESSON

1.1

98-366 Networking Fundamentals 

Bus mastering is supported by many bus architectures that enable a device connected to the bus to initiate transactions.



Devices with Ethernet communicate like they were in chat room, which is called carrier sense multiple access/ collision detection (CSMA/CD).



Two packets are sometimes sent (two cards talk) at the same time.



The cards arbitrate on their own to decide which one will resend its packet first when this collision occurs.



All PCs share the data transfer capacity of that bandwidth (wire ) if they are on a bus network.

LESSON

1.1

98-366 Networking Fundamentals

Advantages of a Bus Network 

Easy to implement and extend



Well-suited for temporary or small networks not requiring high speeds (quick and easy setup)



Cost effective; only a single cable is used



Cheaper than other topologies



Easy identification of cable faults

LESSON

1.1

98-366 Networking Fundamentals

Disadvantages of Bus Networks 

Limited cable length and number of stations



Only one packet can remain on the bus during one clock pulse



If there is a problem with the cable, the entire network breaks down.



Performance degrades as additional computers are added or with heavy traffic



Slower data transfer rate than other topologies



It works best with limited number of nodes

LESSON

1.1

98-366 Networking Fundamentals

Hybrid Network 

When a combination of two or more topologies are connected



If two star networks were connected together, they would exhibit a hybrid network topology. o

A star ring network would be two or more star topologies linked together using a multistation access unit (MAU) as a centralized hub.

LESSON

1.1

98-366 Networking Fundamentals 

Two or more star topologies connected using a bus trunk would be a star-bus network.



A multi-station access unit (MSAU) connects a group of computers to a token ring local area network.

LESSON

1.1

98-366 Networking Fundamentals

Lesson Review 

Use the Student Activity brain map document



Work in small groups (3–4 students) to discuss the completed brain map



Select a presenter to tell about the network topology applications which your group decided was appropriate for various scenarios



Share one scenario and describe how the topology your group selected is ideal for this scenario

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Understand Switches

LESSON

1.1

98-366 Networking Fundamentals

Lesson Overview In this lesson, you will learn about: 

Switches



Transmission speeds



Data transmission



Cables



Uplink speeds



Managed and unmanaged switches



VLANs

LESSON

1.1

98-366 Networking Fundamentals

Anticipatory Set 

A traditional light switch control has only 2 settings—on or off. A dimmer switch control allows for variations of light intensity. Think about these two variations of controls and what you have already learned about network hubs and switches. Explain what you think the difference is between a network hub and switch.



Form groups of three to discuss your answers.

LESSON

1.1

98-366 Networking Fundamentals

Switches 

A computer networking device that connects network segments



Some make it possible to connect different types of networks, including Ethernet, fiber channel, ATM, ITU-T G.hn and 802.11.

LESSON

1.1

98-366 Networking Fundamentals 

Layer 2 switches are network bridges that process and route data at the data link layer (layer 2) of the OSI model.



Layer 3 switches (multilayer) process data at the network layer of 3 and above.



Layer 4 switches allows for policy-based switching and are based on the OSI "transport" layer. These switches limit different types of traffic on specific end-user switch ports. o

The Layer 4 network switch does not work with unintelligent or passive network devices such as hubs and repeaters.

LESSON

1.1

98-366 Networking Fundamentals

Open System Interconnection (OSI) 

A way of subdividing a communications system into smaller parts (called layers)



Layers are defined when services are provided to the layer above it and receive services from the layer below it.



On each layer an “instance” provides services to the instances at the layer above and requests service from the layer below.



A repeater is an electronic device that receives a signal and retransmits it to the other side of an obstruction or to a higher level or at a higher power so that the signal can cover greater distances.

LESSON

1.1

98-366 Networking Fundamentals

Transmission speed 

Data are moved across a communications channel at different rates.



The rate is referred to as the bandwidth.

LESSON

1.1

98-366 Networking Fundamentals

Data Transmission 

A standard 10/100 Ethernet switch operates at the data-link layer of the OSI model to create a different collision domain for each switch port.



Ethernet is a family of frame-based computer networking technologies for local area networks.



In the Ethernet networking protocol a collision domain is a physical network segment where data packets can "collide" with one another when being sent.

LESSON

1.1

98-366 Networking Fundamentals 

A network collision is where one particular device sends a packet on a network segment, forcing every other device on that same segment to pay attention to it.



The hub runs in half duplex sharing bandwidth, resulting in collisions, which would then necessitate retransmissions. o



A half duplex is a system where only one device can talk to another at one time—they take turns talking.

Using a switch is called microsegmentation. o

Allows for dedicated bandwidth with every computer on point-topoint connections

o

Can run in full duplex with no collisions

LESSON

1.1

98-366 Networking Fundamentals

Cables 

A straight-through cable has identical ends.



A crossover cable has different ends.



A PC can be connected to an uplink port with a crossover cable and to a regular port with a straight-through cable.

LESSON

1.1

98-366 Networking Fundamentals

Uplink Speeds 

Ethernet standards on uplink speeds are of 10Mbps, 100Mbps, 1000 Mbps/1Gbps, 10Gbps since switches come with autosensing in various combinations.



The access switch members have an uplink module installed. o



There are two ports on each uplink module.

The uplinks are configured to act as trunk ports by connecting the access switch with the distribution switch.

LESSON

1.1

98-366 Networking Fundamentals

Managed and Unmanaged Switches 

An unmanaged switch is also called “dumb”—it allows all traffic to go through the network and the administrator has no control.



The system administrator can take control of the network with a managed switch and allow ports to talk to other ports or none at all.



The switch's benefits over a hub include full bandwidth to each port and methods to deal with collisions.



The ports are allowed to talk to the print server or the personal computers.



A managed switch has its own IP address, and has a telnet and maybe a web-based interface to monitor and secure access to each port on the switch.



A managed switch can also be used to enable or disable specific ports without unplugging a cable.

LESSON

1.1

98-366 Networking Fundamentals 

A managed switch can have virtual LANS (VLANs), which separate ports on a switch into different switches.



A managed switch can tell you about excessive usage on certain ports.



A managed switch can be used to limit the number of IP addresses that one port can service.

LESSON

1.1

98-366 Networking Fundamentals

Virtual LAN (VLAN) 

Allows a separate logical network connectivity from a physical connectivity



Not limited by its physical connectivity



All users belong to a single broadcast domain and can communicate with each other at the data link layer or “layer 2.”



Can be used to segment a complex network into smaller units for better manageability, improved performance, and security



The ability to move is much simpler because of the dynamic nature of VLANs—no physical changes to network topology are necessary.



Security domains can be constructed to provide various levels of security in the network.

LESSON

1.1

98-366 Networking Fundamentals Virtual LAN using VLANs to create broadcast domains across switches

LESSON

1.1

98-366 Networking Fundamentals

Hubs vs. Switches 

A hub is like an ordinary junction box and just passes along what it receives to all the other ports (connections) on the hub.



A switch is more intelligent and is selective about where it passes data. o

It learns where certain equipment is located and passes along the data only to the ports that need to receive it, allowing multiple interactions at once.

LESSON

1.1

98-366 Networking Fundamentals

Lesson Review Directions to the student: 1.

Complete NetFund_SA_2.1A

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Understand Switches

LESSON

1.1

98-366 Networking Fundamentals

Lesson Overview In this lesson, you will learn about: Switches

Backplane Hardware

speed

redundancy

Layer

2 and layer 3 switches

MAC

table

Security

options

Switching

types

Support Capabilities

of hubs vs. switches

LESSON

1.1

98-366 Networking Fundamentals

Anticipatory Set Recall what you learned about networking and switches. 1.

Explain when you would use a hub rather than a switch

2.

List reasons for using an unmanaged switch

Form a group of three and discuss your responses

LESSON

1.1

98-366 Networking Fundamentals

Switches 

A switch is a network bridge that processes and routes data at the data link layer (layer 2) of the OSI model.



Large switches have higher layer issues, router issues, backplanes, security and redundancy.



Built-in or modular interfaces in large switches make it possible to connect different types of networks, including Ethernet, Fiber Channel, ATM, ITU-T G.hn and 802.11.

LESSON

1.1

98-366 Networking Fundamentals

Layer 2 Switch 

Provides the same functionality as bridges



Learns and forwards frames on each port just like a multiport bridge



Multiple switching paths inside the switch can be active at the same time.



Operates utilizing MAC addresses in its caching table to quickly pass information from port to port.

LESSON

1.1

98-366 Networking Fundamentals

LESSON

1.1

98-366 Networking Fundamentals

Layer 3 Switch 

Utilizes IP addresses to perform the functions as layer 2 switches



Are fast routers that do layer 3 forwarding in hardware



Because IP is the most common among all layer 3 protocols today, most of the layer 3 switches perform IP switching at the hardware level and forward the other protocols at layer 2 (bridge them).

LESSON

1.1

98-366 Networking Fundamentals

Bridging 

Involves segmentation of local-area networks (LANs) at the Layer 2 level



A multiport bridge learns about the media access control (MAC) addresses on each of its ports and transparently passes MAC frames destined to those ports.



Ensures that frames destined for MAC addresses that lie on the same port as the originating station are not forwarded to the other ports

LESSON

1.1

98-366 Networking Fundamentals

Switch Security 

Define virtual local area networks



Two basic steps: 1.

Defining what users can see

2.

Defining where they can connect



What you see—Security allows organizations to separate sensitive clusters of systems from the rest of the network.



What you connect—Port security is available on business-class switches and some allow in-depth settings.

LESSON

1.1

98-366 Networking Fundamentals

Hardware Redundancy 

Occurs when segment C is added to the network connecting switches A and C



If one of the switches fails, the network will eliminate the point of failure.

LESSON

1.1

98-366 Networking Fundamentals

Managed Switches 



Provide support for the network through: o

Flexibility

o

Security

o

Reliability

o

Expandability

Switches are supported by their manufacturer and with online manuals.

LESSON

1.1

98-366 Networking Fundamentals

Three Types of Switching 

Circuit



Packet



Cell Relay

Circuit switching 

Used in voice networks



Not an efficient method for routing any kind of data



Is wasted because no transmission is using the bandwidth of the circuit 100 percent of the time



In circuit failure during a transmission, the entire connection must be re-established, which means the conversation must start over again.

LESSON

1.1

98-366 Networking Fundamentals

Packet Switching 

Used in data networks



Has no dedicated circuits



Each circuit carries many transmissions at the same time.



Has the ability to route data units over any route



More reliable because if a particular circuit in the network should fail, the routers in the network route data units over different circuits.



The protocols have the ability to reassemble the data units into their proper order.

LESSON

1.1

98-366 Networking Fundamentals

Switching Principles 

Cell relay



Voice



Data transmission



The cell is the data unit.



Voice requires small data units.



o

In order to support voice, the data units must be small so that they can be processed quickly and sent through the network with minimal delay.

o

Whenever there is information to be transmitted, the switch simply sends the data units.

Data favors large data units.

LESSON

1.1

98-366 Networking Fundamentals

Lesson Review 1.

Why it is preferable to use a switch rather than a hub?

2.

List reasons for using a managed switch versus an unmanaged switch.

LESSON

21 . 2 1

98-366 98-366Networking NetworkingFundamentals Fundamentals

Understand Routers

LESSON

1.1

98-366 Networking Fundamentals

Lesson Overview In this lesson, you will learn about: 

Directly connected static routes



Dynamic routes (routing protocols)



Default routes, NAT, RRAS



Routing tables



Routing protocol



Routing in Windows Server



Transmission speed considerations

LESSON

1.1

98-366 Networking Fundamentals

Anticipatory Set 

Be creative and think about what a “route” means to you and what controls your route through life. There is probably a router telling you what to do such as a traffic light that tells you to go, slow down, or stop.



Give other examples of routers and their applications that you have encountered



Share your answers with two others. Does everyone have router experiences?



Begin brainstorming how you would use a router in the computer industry

LESSON

1.1

98-366 Networking Fundamentals

Routers 

A device that selectively interchanges packets of data in two or more computer networks while connecting the networks



Connected to at least two networks, generally two LANs or WANs or a LAN and its ISP's network



Wireless routers provide everything that a wired router provides, including ports for Ethernet connections and the attributes for wireless security such as Wi-Fi Protected Access (WPA) and wireless MAC address filtering.



Many wireless routers can be configured for "invisible mode" so that your wireless network cannot be scanned by outside wireless clients.

LESSON

1.1

98-366 Networking Fundamentals 

Data can be transmitted through the router from place to place at a measured kilobits transmission speed called the bandwidth .



Each interface on a router will impact overall performance, especially WAN connections.



Data rate and data speed are the same in terms of transmission speed.



Compared to data transmission, bandwidth or "capacity" means how wide the pipe is and how quickly the bits can be sent.



These "speeds" are aggregate speeds. The data on the multiple signal channels are assigned by channel for different uses.



Data transmission speed (or bandwidth) is measured in kilobits, 1,000s of bits per second, or megabits, Mbps, millions of bits per second.



Because of software and protocols, actual transfers are considerably lower.

LESSON

1.1

98-366 Networking Fundamentals

Routing 

A routing protocol is applied when passing data from one subnet (interface) to another subnet.



When determining which route is preferable, directly connected networks have the highest priority, followed by static routes, and then other routes.



If a corresponding interface command is contained under the router configuration stanza of that protocol, it is are advertised by IGP routing protocols, which are directly connected networks.



IGP—Interior gateway protocol describes the fact that each system on the Internet can choose its own routing protocol.

LESSON

1.1

98-366 Networking Fundamentals

Static Routing 

The process of manually entering routes into the routing table through a configuration file that is loaded when the routing device starts up



Static routes are manually configured and cached when a router starts up and don’t change unless a user changes them.



Static routing does not handle down connections well because they must be reconfigured manually to repair any lost connectivity.



Does not work well when the routing information has to be changed or needs to be configured on a large number of routing devices.

LESSON

1.1

98-366 Networking Fundamentals

Dynamic Routing Protocols 

Software applications that dynamically discover network destinations and how to get to them



Have the ability to adapt to logical network topology changes, equipment failures, or network outages.

1.

A router will “learn” routes to all directly connected networks first.

2.

Secondly it will learn routes from other routers that run the same routing protocol.

3.

Next the router sorts through its list of routes and selects one or more “best” routes for each network destination it knows or has learned.

4.

Finally, dynamic protocols will distribute this “best route” information to other routers running the same routing protocol.

LESSON

1.1

98-366 Networking Fundamentals

Routing Table 

Routing Information Base (RIB) is an electronic table (file) or that is stored in a networked computer or a router.



The routes to network destinations are stored in the routing table.



The function of the routing protocols and static routes is to create the routing tables.



The most specific route to the destination IP address is the longest matching route.



The router uses the lowest metric to select the best route when multiples occur.



The router is free to choose which table entry to use if multiple entries exist that are the longest match and the lowest metric.

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98-366 Networking Fundamentals 

TCP/IP network routers use the routing table to calculate the destinations of messages it is responsible for forwarding.



A computer must have an IP address to communicate with other computers and servers on the Internet.



An IP address (Internet protocol) is a unique 32-bit number that identifies the location of your computer on a network.



With the growth of the Internet and increased use, the number of available IP addresses is not enough—redesign for the address format to allow for more possible addresses is being developed (IPv6) and it will require modification of the entire infrastructure of the Internet.

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

The network address translation (NAT) is the process of modifying network address information while in transit across a traffic routing device.

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Routing and Remote Access in Windows Server 

Routing and remote access service (RRAS) in Windows Server supports remote user or site-to-site connectivity.



RRAS is an open platform for routing and networking.



By using secure VPN connections, routing services are provided to businesses in LAN and WAN environments or over the Internet.



Routing is used for multiprotocol LAN-to-LAN, LAN-to-WAN, VPN, and network address translation (NAT) routing services.



By using RRAS, VPN connections can be deployed to provide end users with remote access to your organization's network.



A site-to-site VPN connection between two servers at different locations can also be created.

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Lesson Review 1.

Complete NetFund_SA_2.2

2.

Exchange papers and check the answers as the teacher reviews them

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Understand Media Types Part 1

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Lesson Overview In this lesson, you will learn information about: • Network media types • Cable types and their characteristics • Fiber optics • Susceptibility to external interference • Susceptibility to electricity

• Susceptibility to interception

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98-366 Networking Fundamentals

Activating prior knowledge 1.

Compare these 2 images of cables.

2.

Discuss the implications of each in your small group.

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Anticipatory Set Network Media types 

Media is the actual physical environment through which data travels as it moves from one component to another and connects network devices.



Two categories of Media are cable network and wireless network.



To determine what transmission media is right for particular networking environment you need to consider: o

Required throughput

o

Cabling distance

o

Noise resistance

o

Security

o

Flexibility

o

Plans for growth

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Common Network Cable Media 

Twisted-pair cable (shielded, unshielded, stranded copper, solid core copper)



Coaxial cable and RFI



Fiber-optic cable



Wireless

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Twisted pair cables 

Available unshielded (UTP) or shielded (STP)



STP is used in noisy environments where the shield is around each of the wire pairs, plus an overall shield protects against excessive electromagnetic interference.



A variation of STP, known as ScTP for "screened twisted pair" or FTP for "foil twisted pair," uses only the overall shield and provides more protection than UTP, but not as much as STP.



Both UTP and STP come in Stranded and Solid wire. o

The stranded copper wire is very flexible.

o

Solid wire cable has less attenuation and can span longer distances.

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Coaxial cables 

Were the first cables used in Ethernet networks.



Consists of an insulator that separates the braided inner conductor and the outer conductor, which is a woven copper braid



Commonly used for cable TV connections and10 Base5 and 10 Base2 Ethernet networks.



Coaxial Thinnet supports a maximum segment length of 185 meters, is less costly and easier to install



Coaxial Thicknet can send signals up to 500 meters, is costlier and demands more efforts in installation



The transmission speed these cables provide is between 2.5 Mbps and 10 Mbps.



Coaxial cables are more resistant to EMI than the UTP cable, because of greater insulation to external interference.

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Fiber Optics 

Cables are made up of glass or other light transmitting material.



Transmit data in the form of light



A reflective coating that allows light beams to travel without outer interference covers the glass cable.



The advantages: o

Faster

o

Very long distances without the risk of outer interference



At one end of the fiber optics system is a transmitter that accepts coded electronic pulse data coming from copper wire.



The information is processed and translated into equivalently coded light pulses.



A light-emitting diode (LED) or an injection-laser diode (ILD) can be used for generating the light pulses.

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1.1

98-366 Networking Fundamentals 

Fiber optic cable construction has these elements: core, cladding, coating, strengthening fibers, and a cable jacket.



The center is glass fiber, the second ring is a fiber coating, and third ring is a thermoplastic over coating or buffer, the fourth ring is an Aramid strength member and the last ring has a PVC jacket or a fluoride copolymer jacket.

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98-366 Networking Fundamentals 



Single mode fiber (SMF) optic cable and multi-mode fiber (MMF): o

SMF supports high-speed LAN covering long distances and WAN spread over different buildings or cities.

o

Used in 10GBase-LR Ethernet specification, which runs at the speed of 10 Gbps and allows only one mode of light to transmit.

The multi-mode fiber (MMF) optic cable : o

Used for high-speed networks spread over short distances

o

Used for 10GBase-SR Ethernet standard that supports the transmission speed of 10 Gbps, it allows the light signals to travel in more than one path

o

Less costly than the SMF cable

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Wireless communication 

The transfer of information over a distance without the use of physical media



The distances involved may be short (a few meters as in television remote control) or long (thousands or millions of kilometers for radio communications)



Wireless communication is considered to be a branch of telecommunications

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External Interference 

Interference in telecommunication and electronics refers to anything that alters, modifies, or disrupts a message as it travels along a channel between a source and a receiver.



External susceptibility comes from machinery and power cables.



Tightly strapped cabling often causes interference from motors and solenoids jumping over to the signal cabling and disturbing sensors. o



Jumping occurs when the high current can cause the rapid release of large volumes of hydrogen, which can be ignited by a nearby spark.

See examples of external interference from equipment and cables at www.qedata.se/e_emi_bakgrund.htm.

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Electromagnetic interference (EMI) 

Undesirable electromagnetic emission or any electrical or electronic disturbance.



EMI can be man-made or natural and interrupts, obstructs, or otherwise degrades or limits the effective performance of electronics and electrical equipment.



The source may be any object, artificial or natural, that carries rapidly changing electrical currents, such as an electrical circuit, the Sun or the Northern Lights.

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1.1

98-366 Networking Fundamentals 

Twisted pair’s susceptibility to electromagnetic interference greatly depends on the pair twisting schemes staying intact during the installation.



As a result, twisted pair cables usually have stringent requirements for maximum pulling tension as well as minimum bend radius.



The fragility of twisted pair cables makes installation practices an important part of ensuring the cable’s performance.

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Interception 

Data communication equipment emits modulated signals that carry information that an eavesdropper or hacker can intercept. o



It is completely undetectable, requires little apparatus, and can be done at a considerable distance.

Like fiber optics but without the fiber, LED indicators act as little freespace optical data transmitters.

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Lesson Review •

Create a list of the networks in your home, school, or place of work.

•

Speculate about the types of interference susceptibility that each might be vulnerable to.

•

Compare your ideas with your partner.

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Understand Network Media Types Part 2

LESSON

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Lesson Overview In this lesson, you will learn information about: 

Cabling



Category 5e cable



Coaxial cable



RJ-45



Thicknet cable



Thinnet coaxial cable



Twisted pair shielded cable



Unshielded cable

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Anticipatory Set 1.

Recall what you learned about cables yesterday.

2.

On paper list everything you remember about twisted pair cables.

3.

Share your answers in a group and present to the class if time allows.

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Preparing for a Class Activity 

Students will make a cable at the end of this review using a category 5 cable and RJ-45 terminators.



Keep notes on the demonstration and presentation for your cable making.

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Unshielded twisted pair cable (UTP) 

8 individual copper wires covered by an insulating material



Used for many different networks.



The copper wire is color-coded plastic insulation and they are twisted in pairs. It is all covered with an outer jacket.

LESSON

1.1

98-366 Networking Fundamentals 

UTP is the most common form of twisted pair wiring.



It is less expensive and easier to work with than STP.



It is used in Ethernet 10Base-T and 100Base-T networks, as well as in home and office telephone wiring.



Two insulated copper wires are twisted around each other to decrease crosstalk or electromagnetic induction between pairs of wires.



Every signal on a twisted pair involves both the wires.



Twisted pair is installed in two or more pairs, all within a single cable, to offer multiple connections to computers.



UTP cable is typically installed using a registered jack 45 (RJ-45) connector.



The RJ-45 is an eight-wire connector used commonly to connect computers onto a local area network (LAN), especially Ethernets.

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Types of UTP Cabling 

Category 1—Used for telephone communications



Category 2—Data speed at 4 Mbps per second



Category 3—Speeds of 10 Mbps, used for 10BASE-T



Category 4—For Token Ring – transmit data at 16 Mbps



Category 5—Can transmit data at speeds up to 100 Mbps



Category 5e —Used in networks running at speeds up to 1000 Mbps (1 gigabit per second [Gbps])



Category 6—Consists of four pairs of 24 American wire gauge (AWG) copper wires and fastest standard for UTP

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Shielded twisted-pair (STP) 

Used in Ethernet networking and has shielding, cancellation, and wire twisting with each pair of wires wrapped in a metallic foil



The four pairs of wires are wrapped in an overall metallic braid or foil, generally 150-ohm cable.

LESSON

1.1

98-366 Networking Fundamentals 

Because of its cost and difficulty with termination, STP is rarely used in Ethernet networks.



STP is primarily used in Europe.



Because most buildings are already wired with UTP, many transmission standards are adapted to use it, to avoid costly rewiring with an alternative cable type.



UTP and STP are not used together.

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Coaxial cable • Made of a hollow outer cylindrical conductor surrounding a single inner wire made of two conducting elements • One element in the center of the cable is a copper conductor. • A layer of flexible insulation surrounds the copper conductor. • Over the insulation is a metallic foil or woven copper braid acting as both the second wire in the circuit and a shield for the inner conductor . • This second layer/shield helps reduce the amount of outside interference.

LESSON

1.1

98-366 Networking Fundamentals 

Coaxial cable can be cheaper for a physical bus topology because less cable will be needed.



It is more costly than UTP on a per-unit length and is relatively inexpensive.



Coaxial cable is less expensive than fiber optic cable.



Can be used over longer distances than twisted-pair cable



Ethernet can run approximately 100 meters using twisted-pair cabling. Using coaxial cable increases this distance to 500 meters.



Can be run with fewer boosts from repeaters for longer distances between network nodes than either STP or UTP cable

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Wireless communication Uses radio frequencies (RF) or infrared (IR) waves to transmit data between devices on a LAN Wireless signals are electromagnetic waves that can travel through the vacuum of outer space and through a medium such as air. A key module is the wireless hub for distributing signals through the wireless LAN. A computer can have a wireless adapter card (wireless NIC) installed to receive the signals from the access point.

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Applications of wireless data communication 

Accessing the Internet using a cellular phone



Establishing Internet connection over satellite



Beaming data between two handheld computing devices



Wireless keyboard and mouse for the PC



Wireless LAN (WLAN) use radio waves (902 MHz)



Microwaves (2.4 GHz)



IR waves (820 nanometers [nm]) for communication

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Wireless Distribution

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98-366 Networking Fundamentals

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98-366 Networking Fundamentals

Demonstration and Class Activity Preparation 

Unshielded twisted pair cable (UTP) cable has eight individual copper wires covered by an insulating material; used for many different networks.



The copper wire is color-coded plastic insulation and the wires are twisted in pairs. It is all covered with an outer jacket.

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98-366 Networking Fundamentals



Color coding of wiring pairs

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98-366 Networking Fundamentals

Network Cabling Standards 

The Electronic Industries Alliance (EIA) developed standards in 1991 for the cabling used in telecommunications applications.



In 1995 it was updated by the EIA and later replaced with the current TIA/EIA 568-B standard.

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98-366 Networking Fundamentals

T568A and T568B 

Based on TIA/EIA-568-B.1-2001, the wiring schemes define the pin out, or order of connections, for wires in eight-pin modular connector plugs and jacks.

LESSON

1.1

98-366 Networking Fundamentals 

The wiring assignments in the RJ-45 plug are important. A colored wire must be placed in a specific pin location in the plug in order for the cable to meet the standard.



It is these wiring assignments that differ between the T568A and T568B standard.



The only difference between T568A and T568B is that pairs 2 and 3 (orange and green) are swapped.



Both configurations wire the pins "straight through," i.e., pins 1 through 8 on one end are connected to pins 1 through 8 on the other end.



The same sets of pins are paired in both configurations: pins 1 and 2 form a pair, as do 3 and 6, 4 and 5, and 7 and 8.

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98-366 Networking Fundamentals

Cable Termination 

Cables that are terminated with differing standards on each end will not function normally.



Standard RJ-45 pinouts describe the arrangement of the individual wires required when connecting connectors to a cable.



RJ-45 is the standard connector for 10Base-T/100Base-TX Ethernet, ISDN, T1, and modern digital telephone systems.

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98-366 Networking Fundamentals

Demonstration Steps 1.

The pins on the RJ-45 plug are numbered 1 to 8.

2.

Hold a CAT 5 patch cable in your hand, as if inserting into a jack, with the contacts facing in the up position; pin 1 will be on the far left.

3.

Pin 8 will be the pin on the far right. We follow this orientation when we define the wiring assignments in the RJ-45 plug.

4.

CAT 5 Cable has four twisted pairs within the sheath. Each pair has a specific color code, and is placed into deliberate pin location within the RJ-45 plug.

5.

In constructing the cable, use identical pin assignments on each end as the 568-B standard is used in the United States.

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Deciding to use T568 A or T568 B 1.

If the installation is residential, choose T568A unless other conditions apply.

2.

If there is preexisting voice/data wiring (remodel, moves, adds, changes), duplicate this wiring scheme on any new connection.

3.

If project specifications are available, use the specified wiring configuration.

4.

If components used within the project are internally wired either T568A or T568B, duplicate this wiring scheme.

Circulate and carefully inspect the finished demonstration cable.

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Student Activity 2.3_B 1.

Group in pairs so each person can attach an RJ-45 end to the category 5e cable.

2.

View the YouTube video on making a patch cord with RJ-45 terminators and a category 5e cable wire. http://www.youtube.com/watch?v=482VtesZwZ8

3.

Complete Student Activity 2.3_B with a partner to construct a cable using the materials provided.

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Lesson Review 1.

Test the cable.

2.

Analyze and correct any problems.

3.

Detail the testing and correcting process in a written report.

4.

Submit to your instructor.

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Understand the OSI Model Part 1

LESSON

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Lesson Overview In this lesson, you will learn about: •

Internetwork

•

IETF

•

ISO/OSI

•

ITU-T

•

Protocols

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Anticipatory Set 1.

Problem: Personal computer use and the Internet have grown very quickly. Corporations and educational users are developing large networks and individuals access the Internet in huge numbers. There is no pattern or organization, and networks have developed without planning.

2.

Assignment: Think about how you might resolve the complicated issues that have arisen. List some of your ideas for unclogging and making the Internet smoother for corporations, educational institutions, and individuals.

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Internetwork •

A collection of individual networks, connected by intermediate networking devices, that functions as a single large network

•

Formed from different kinds of network technologies that can be interconnected by routers and other networking devices

•

Offers a solution to three key problems:

•

o

Isolated LANs

o

Duplication of resources

o

A lack of network management

Many issues including configuration, security, redundancy, reliability, centralization, and performance, must be adequately dealt with for the internetwork to function smoothly.

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98-366 Networking Fundamentals

ISO (International Organization for Standardization) •

The world's largest developer and publisher of International Standards. ISO is now considered the primary architectural model for intercomputer communications.

OSI (Open System Interconnection model) •

Defines a networking framework for implementing protocols in seven layers

ITU-T (International Telecommunications Union-Telecommunication) •

The standardization division of the ITU that develops communications recommendations for all analog and digital communications

IETF (Internet Engineering Task Force) •

Charged with studying technical problems facing the Internet and proposing solutions to the Internet Architecture Board ; the standards agency for TCP/IP

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98-366 Networking Fundamentals

Open System Interconnection (OSI) Reference Model •

•

How information from a software application in one computer moves through a network medium to a software application in another computer. In the International Organization for Standardization Open Systems Interconnection (ISO/OSI) model for network communications, WNet functions operate across the presentation and session layers.

LESSON

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98-366 Networking Fundamentals

The data enter as they transmit, going down the seven layers, and exit as they are received at the right, going up the layers.

Image courtesy of The Abdus Salam International Centre for Theoretical Physics.

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Characteristics of the OSI Layers •

Each of the seven layers of the OSI reference model can be divided into two categories: upper layers and lower layers.

•

Application issues implemented only in software is part of the upper layer of the OSI model. It is the highest layer and closest to the end user.

•

Software applications that contain a communications component are used both by the users and the application layer process.

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Protocols •

A set of rules that direct the way computers exchange information

•

Communication protocols enable communication and execute the functions of one or more of the OSI layers. o

At the physical and data link layers of the OSI model LAN protocols define communication over the various LAN media.

o

At the lowest three layers of the OSI model WAN protocols define communication over the various wide-area media.

o

Routing protocols control the exchange of information between routers so that the routers can select the proper path for traffic.

o

Network protocols apply to various upper-layer protocols.

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OSI Model and Communication Between Systems •

The OSI layers are where information being transferred from a software application in one computer system to a software application in another must pass.

•

The application layer then passes the information to the presentation layer (Layer 6), which sends the data to the session layer (Layer 5), and so on down to the physical layer (Layer 1).

•

At the physical layer, the data are placed on the physical network medium and are relayed across the medium to System 2.

•

The physical layer of System 2 removes the data from the physical medium, and then passes the information up to the data link layer (Layer 2), which passes it to the network layer (Layer 3), and so on, until it reaches the application layer (Layer 7) of System 2.

•

Lastly, the application layer of System 2 passes the data to the recipient application to complete the communication process.

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Interaction Between OSI Model Layers •

•

A specified layer in the OSI model generally communicates with three other OSI layers: o

the layer directly above it

o

the layer directly below it

o

its peer layer in other networked computer systems

The data link layer in System 1, communicates with the network layer of System 1, the physical layer of System 1, and the data link layer in System 2.

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OSI Layer Services •

One OSI layer communicates with another layer to make use of the services provided by the second layer.

•

The services provided by adjacent layers help a given OSI layer communicate with its peer layer in other computer systems.

•

Three basic elements are involved in layer services: 1.

2.

3.

The service user—Layer that requests services from the next OSI layer The service provider —Layer that provides services to service users

The service access point (SAP) —Intangible place at which one OSI layer can request the services of another layer.

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Encapsulation •

The OSI Model Layers and Information Exchange is done by the use of communication control to communicate with the peer layers in other computer systems and consists of specific requests and instructions that are exchanged between peer OSI layers.

•

The data portion of an information unit at a stated OSI layer can contain headers that have been passed down from upper layers.

•

The data that has been passed down from upper layers are appended to trailers.

•

The data portion of an information unit at a given OSI layer can contain headers, trailers, and data from all the higher layers. This is known as encapsulation.

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Lesson Review Student ActivityNetFund_SA_3.1_A Understanding Protocols and Services

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98-366 Networking Fundamentals

Class Activity: How well do you really know the OSI networking model? 1.

Test yourself with our OSI Model game. http://www.gocertify.com/games/osi-game.shtml

2.

Complete the review at the end of each game and record any missed questions with the correct answer to either turn in or discuss with the whole class.

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Understand the OSI Model Part 2

LESSON

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Lesson Overview In this lesson, you will learn information about: •

Frames

•

Packets

•

Segments

•

TCP

•

TCP/IP Model

•

Well-known ports for most-used purposes

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98-366 Networking Fundamentals

Anticipatory Set Review and discuss the role of the following items in OSI: application

presentation

session

transport

network

data link

physical If you complete the work, you may review the OSI Networking Game http://www.gocertify.com/games/osi-game.shtml

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The Internet Protocol Suite •

Includes Transmission Control Protocol (TCP) and Internet Protocol (IP) and is referred to as TCP/IP model.

•

Defines general guidelines and implementations of specific networking protocols to enable computers to communicate over a network for common applications (electronic mail, terminal emulation, and file transfer)

•

Each layer of the TCP/IP model corresponds to layers of the seven-layer OSI reference model proposed by the ISO.

•

Ipsec (Internet Protocol Security) is a dual mode, end-to-end, security scheme operating at the Internet Layer of the Internet Protocol Suite or OSI model Layer 3.

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The TCP/IP is shown in relation to the OSI seven layers. TCP delivers an unstructured stream of bytes identified by sequence numbers with stream data transfer.

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TCP/IP •

Provides end-to-end connectivity specifying how data should be formatted, addressed, transmitted, routed, and received

•

Protocols exist for a variety of communication services between computers.

•

The layers near the top are closer to user application, the layers near the bottom are closer to the physical transmission of the data.

•

Viewing layers as providing or consuming a service is a method of abstraction to isolate upper layer protocols.

•

The lower layers avoid having to know the details of each and every application and its protocol.

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Transmission Control Protocol (TCP) •

Assembles bytes into segments and passes to IP for delivery

•

Provides end-to-end reliable packet delivery through an internetwork

•

Mechanisms deal with lost, delayed, duplicate, or misread packets.

•

Time-out mechanisms detect lost packets and request retransmission.

•

Provides proficient flow control. o

•

When sending responses back to the source, the receiving TCP process indicates the highest sequence number it can receive without overflowing its internal buffers.

Full-duplex operation processes can both send and receive at the same time. o

Multiplexing means that numerous concurrent upper-layer conversations can be occurring over a single connection.

LESSON

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98-366 Networking Fundamentals •

Each host on a TCP/IP network is assigned a unique 32-bit logical address that is divided into two main parts: 1.

2.

Network number – identifies a network and must be assigned by the Internet Network Information Center (InterNIC) if the network is to be part of the Internet Host number – identifies a host on a network and is assigned by the local network administrator

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Internet Protocol (IP) •

A network layer (Layer 3) protocol that contains addressing information and some control information that enables packets to be routed

•

IP is documented in RFC 791 – Request For Comments for Internet Protocol, the specification for how traffic travels over the internet and is the primary network layer protocol in the Internet protocol suite

•

Allows large data transfer so file applications do not have to cut data into blocks

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Well-Known Ports •

Most services work with TCP/IP by configuring the server to use a well-known port number.

•

The client connects from a random high port.

•

Most of these well-known ports are port numbers below 1,024.

•

TCP/IP port assignments on Windows are stored in the \%systemroot%\System32\drivers\etc\services file.

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Examples of known services and ports FTP 20,21 SSH 22 telnet 23 DNS 53 SMTP 25 DHCP 67,68 TFTP 69 HTTP 80 POP2/3 109, 110 NNTP 119 IMAP4 143 HTTPS 443

data transfer secure shell telnet protocol domain name service simple mail transfer protocol dynamic host configuration protocol trivial file transfer protocol hypertext transfer protocol post office protocol 2, 3 network news transfer protocol internet message access protocol hypertext transfer protocol over SSL/TLS

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User Datagram Protocol (UDP) •

Part of the Internet Protocol suite

•

Programs running on different computers on a network can send short messages known as datagrams to one another.

•

A datagram is a self-sufficient and self-contained message sent through the network whose arrival, arrival time, and content are not guaranteed.

•

UDP can be used in networks where TCP is traditionally implemented but is not reliable.

•

Datagrams may go missing without notice, or arrive in a different order from the one in which they were sent.

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IP responsibilities in UDP 1.

Provide connectionless delivery of datagrams

2.

Provide fragmentation and reassembly of datagrams to support data links with different maximum-transmission unit (MTU) sizes o

The maximum transmission unit (MTU) of a communications protocol of a layer is the size in bytes of the largest protocol data unit that the layer can pass onward; a packet is encapsulated into one or more frames, depending upon the MTU size.

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IP Packets •All IP packets are structured the same way – an IP header followed by a variable-length data field. •There are 14 fields in an IP packet header.

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98-366 Networking Fundamentals •

A packet and a frame are both packages of data moving through a network.

•

A packet exists at Layer 3 of the OSI Model, a frame exists at Layer 2 of the OSI Model.

•

Layer 2 is the Data Link Layer – the best-known protocol in this layer is Ethernet.

•

Layer 3 is the Network Layer – the best-known protocol in this layer is IP (Internet Protocol).

•

The TCP segment, encapsulates all higher level protocols above it, a segment at the transport layer and the TCP counterparts for these three items.

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Lesson Review Complete Student Activity NetFund_SA_3.1_B.

LESSON

31 . 2 1

98-366 98-366Networking NetworkingFundamentals Fundamentals

Understand IPv4

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98-366 Networking Fundamentals

Lesson Overview In this lesson, you will learn about:  APIPA  addressing  classful IP addressing and classless IP addressing  gateway  IPv4

 local loopback IP  NAT  network classes  reserved address ranges for local use

 subnetting  static IP

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Anticipatory Set 1.

Write the address range and broadcast address for the following subnet: Subnet: 192.168.1.128 / 255.255.255.224 Address Range? Subnet Broadcast Address?

2.

Check your answer with those provided by the instructor. If it is different, review the method of how you derived the answer with your group and correct your understanding.

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IPv4 

A connectionless protocol for use on packet-switched Link Layer networks like the Ethernet



At the core of standards-based internetworking methods of the Internet



Network addressing architecture redesign is underway via classful network design, Classless Inter-Domain Routing, and network address translation (NAT) .



Microsoft Windows uses TCP/IP for IP version 4 (a networking protocol suite) to communicate over the Internet with other computers.



It interacts with Windows naming services like WINS and security technologies.



IPsec helps facilitate the successful and secure transfer of IP packets between computers.



An IPv4 address shortage has been developing.

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Network Classes Provide a method for interacting with the network All networks have different sizes so IP address space is divided in different classes to meet different requirements. Each class fixes a boundary between the network prefix and the host within the 32-bit address.

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Classful Network 

Divides the address space for Internet Protocol Version 4 (IPv4) into five address classes



Each class, coded in the first four bits of the address, defines a different network size or a different network type.



Design for IPv4 – sized the network address as one or more 8-bit groups, resulting in the blocks of Class A, B, or C addresses.

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Classless Interdomain Routing (CIDR) 

A tactic of assigning IP addresses and routing Internet Protocol packets



Allocates address space to Internet service providers and end users on any address bit boundary, instead of on 8-bit segments



IP addresses consist of two groups of bits in the address: 1.

Most significant part is the network address, which identifies a whole network or subnet

2.

Least significant part is the host identifier, which specifies a particular host interface on that network

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98-366 Networking Fundamentals 

Under supernetting, the classful subnet masks are extended so that a network address and subnet mask could specify multiple Class C subnets with one address.



For example, if 1,000 addresses were needed, 4 Class C networks could be supernetted together:



The subnet 192.60.128.0 includes all the addresses from 192.60.128.0 to 192.60.131.255.

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IPv4 Addresses 

Usually written in dot-decimal notation of four octets of the address expressed in decimals and separated by periods



Base format used in the conversion table. Each octet can be of any of the different bases

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Reserved IP Addresses •Three ranges of address are reserved for private networks.

•Ranges are not routable outside of private networks. •Private machines cannot directly communicate with public networks.

•Internet Assigned Numbers Authority (IANA) reserved three blocks of IP address space for private internets. •Confusion results because different authorities name different IP numbers for different addresses.

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IANA Reserved Blocks

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Automatic Private IP Addressing (APIPA) 

When the address block was reserved, no standards existed for mechanisms of address auto-configuration.



Filling the void, Microsoft created APIPA implementation.



APIPA will automatically assign an Internet Protocol address to a computer on which it is installed.



APIPA has been deployed on millions of machines and has become a de facto standard in the industry.



IETF defined a formal standard for this functionality, RFC 3927, entitled Dynamic Configuration of IPv4 Link-Local Addresses.

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Localhost 

The address range 127.0.0.0–127.255.255.255 is reserved for localhost communication (127.0.0.0/8 in CIDR notation).



Addresses within this range should never appear outside a host computer and packets sent to this address.



Addresses are returned as incoming packets on the same virtual network device (known as loopback).



Loopback or Localhost 127.0.0.0 (or 127/8) should not be used as an address for any station; it is used to ping yourself.

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Broadcast Address 

An address that allows information to be sent to all machines on a given subnet



Found by obtaining the bit complement of the subnet mask and performing a bitwise OR operation with the network identifier



Example: To broadcast a packet to an entire IPv4 subnet using the private IP address space 172.16.0.0/12 (subnet mask 255.240.0.0), the broadcast address is 172.31.255.255.

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98-366 Networking Fundamentals 

On a Class A, B, or C subnet, the broadcast address always ends in 255.



Today, there are several driving forces for the acceleration of IPv4 address exhaustion: o

Mobile devices

o

Always-on devices

o

Rapidly growing number of Internet users

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A Gateway Computer Program 

A link between two computer programs allowing them to share information and bypass certain protocols on a host computer



A telecommunications gateway is a computer or a network that allows or controls access to another computer or network.



A default gateway is a way out of the subnet and it is also known as a router.



All traffic that needs to be routed out of the subnet is done through the hosts’ routing tables.

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Static vs. Dynamic IP Addresses 



Static IP address o

When a computer is configured to use the same IP address every time it powers up

o

Manually assigned to a computer by an administrator

Dynamic IP address o

When the computer's IP address is set automatically

o

Assigned either by the computer interface or host software itself, as in Zeroconf, or assigned by a server using Dynamic Host Configuration Protocol (DHCP)

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Lesson Review Complete Student Activity NetFund_SA_3.2

LEESSSSOO L N N3 . 31 _. A1

98-366 98-366Networking NetworkingFundamentals Fundamentals

Understand IPv6 Part 1

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Lesson Overview In this lesson, you will learn about: Addressing Dual

IP stack

Gateway IPv6 ipv4toipv6

tunneling protocols to ensure backwards compatibility

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Anticipatory Set Explain why IPv4 is typically insufficient and why IPv6 is more useful. Form groups of three to discuss your answers.

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Tunneling Protocol Used by computer networks when the delivery network protocol encapsulates a different payload protocol

Teredo o

A tunneling protocol intended to grant IPv6 connectivity to nodes that are located behind IPv6-unaware NAT devices.

o

Identifies a way of encapsulating IPv6 packets within IPv4 UDP datagrams that can be routed through NAT devices and on the IPv4 internet.

o

6to4 is an Internet conversion mechanism for migrating from IPv4 to IPv6, a system that allows IPv6 packets to be transmitted over an IPv4 network with no need to configure explicit tunnels. Special relay servers are also in place that permit 6to4 networks to communicate with native IPv6 networks.

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IPv6 has all zeroes for the middle 16 bits; thus, they start off with a string of 96 zeroes, followed by the IPv4 address.

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ISATAP 

Intra-Site Automatic Tunnel Addressing Protocol



An IPv6 transition mechanism meant to transmit IPv6 packets between dual-stack nodes on top of an IPv4 network o

Uses IPv4 as a virtual nonbroadcast multiple-access network (NBMA) data link layer, so that it does not require the underlying IPv4 network infrastructure to support multicast.

o

The IP6_ADDRESS structure stores an IPv6 address and the IPv6 subnet size has been standardized by fixing the size of the host identifier portion of an address to 64 bits to assist an automatic mechanism for forming the host identifier from Link Layer media addressing information (MAC address).

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Dual IP Stack 

Special addresses assigned to IPv6-capable devices speak both IPv4 and IPv6.



Dual Stack Architecture involves running IPv4 and IPv6 at the same time where end nodes and routers/switches run both protocols.



If IPv6 communication is possible that is the preferred protocol.



Windows uses a dual-stack architecture as shown here.

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Dual IP Stack (continued) A common dual-stack migration strategy used to create the transition from the core to the edge 

Enables two TCP/IP protocol stacks on the WAN core routers, secondly perimeter routers and firewalls, next the server-farm routers, and finally the desktop access routers.



Allows dual protocol stacks on the servers and then the edge computer systems.



Socket can accept connections from both IPv6 and IPv4 TCP clients connecting to port 5001.



This can be seen with IPconfig on an Windows XP or later OS.

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Gateway 

A computer program link between two computer programs so they can share information and bypass certain protocols on a host computer and/or a network that allows or controls access to another computer or network o

Default Gateway—A way out of the subnet; also known as a router

o

Network gateway—An internetworking system that can join two networks that use different base protocols and can be implemented completely in software, completely in hardware, or as a combination

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GLBP (Gateway Load Balancing Protocol) 

Provides automatic router backup for IPv6 hosts configured with a single default gateway on an IEEE 802.3 LAN



Benefits include load sharing, multiple virtual routers, preemption, and authentication.



Can operate at any level of the OSI model depending on the types of protocols they support.



Appears at the edge of a network, capabilities like firewalls tend to be integrated with it.



A broadband router often serves as the network gateway although ordinary computers can also be configured to perform equivalent functions on home networks.

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Internet Protocol version 6 (IPv6) 

An Internet Protocol version designed to succeed IPv4 with an Internet Layer protocol for packet-switched internetworks



The main driving force for the redesign of Internet protocol is the foreseeable IPv4 address exhaustion



IPv6 has a large address space and supports 2128 (about 3.4×1038) addresses



Provides flexibility in allocating addresses and routing traffic, adding a column.



Implements new features that simplify aspects of address assignment and network renumbering.



Subnet size has been standardized as 64 bits, expanded addressing moves us from 32-bit address to a 128-bit addressing method.

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Convert from Hexadecimal to Binary 

Translate each hexadecimal digit into its 4-bit binary equivalent.



Hexadecimal numbers have either and 0x prefix or an h suffix.

For example, the hexadecimal number: 0x3F7A translates to 0011 1111 0111 1010

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The IPv6 packet header is 40 bits long and consists of Version, Class, Flow Label, Payload Length, Next Header, Hop Limit, Source Address, Destination Address, Data, and Payload fields.

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IPv6 Broadcasting Methods Unicast Broadcast 

A communication between a single host and a single receiver



Packets sent to a unicast address are delivered to the interface identified by that address.



There is a one-to-one association between network address and network endpoint: each destination address uniquely identifies a single receiver endpoint.

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Multicast Broadcast 

A communication between a single host and multiple receivers



Packets are sent to all interfaces--to every device on a network.



It is a one-to-many association between network addresses and network endpoints: each destination address identifies a set of receiver endpoints, to which all information is replicated.

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Anycast Broadcast 

A communication between a single sender and a list of addresses



It can contain End Nodes and Routers, and packets are sent to an anycast address.



There is a one-to-"one-of-many" association between network addresses and network endpoints: each destination address identifies a set of receiver endpoints, but only one of them is chosen at any given time to receive information from any given sender.

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Lesson Review Complete Student Activity 3.3_A

LEESSSSOO L N N3 . 31 _. B1

98-366 98-366Networking NetworkingFundamentals Fundamentals

Understand IPv6 Part 2

LESSON

1.1

98-366 Networking Fundamentals

Lesson Overview In this lesson, you will learn about: Ipconfig Local

loopback IP

Ports Packets Subnetting Subnetmask Reserved

address ranges

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1.1

98-366 Networking Fundamentals

Anticipatory Set 1.

Compare the IPv4 with the IPv6 sections of Ipconfig on this Windows 7 screen.

2.

Identify aspects you do not understand.

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1.1

98-366 Networking Fundamentals

Ipconfig 

An Internet protocol configuration in Microsoft Windows that is a console application 1.

Displays all current TCP/IP network configuration values

2.

Refreshes Dynamic Host Configuration Protocol (DHCP)

3.

Refreshes domain name system (DNS) settings



Can be utilized to verify a network connection as well as to verify your network settings



The default displays only the IP address, subnet mask, and default gateway for each adapter bound to TCP/IP.



There are differences with each version of windows.

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Ipconfig in Windows 7 OS

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Ipconfig in Vista OS

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Ipconfig in Windows XP OS IPversion4

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Loopback Device in TCP/IP 

A virtual network interface executed in software only, not connected to any hardware



Any traffic that a computer program sends to the loopback interface is immediately received on the same interface.



IPv6 assigns only a single address for this function, 0:0:0:0:0:0:0:1 (also written as ::1), having the ::1/128 prefix.



The loopback device is 127.0.0.1 for IPv4.



The standard reserved domain name for these addresses is localhost.



Pinging the special address loopback interface is a standard test of the functionality of the IP stack in the operating system.

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Port 

A process-specific software build serving as a communications endpoint and used for multitasking



Used by transport layer protocols such as transmission control protocol (TCP) and user datagram protocol (UDP)



Identified by its port number, the IP address associated with, and the protocol used for communication



Port numbers are divided into three ranges: o

Well-known ports are from 0 through 1023

o

Registered ports are from 1024 through 49151

o

Dynamic and private ports are from 49152 through 65535

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Sample Ports and Allocations

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Packets 

A packet mode is a digital networking communications method grouping all transmitted data into blocks.



Communications links that do not support packets transmit data as a series of bytes, characters, or bits alone.



When data is formatted into packets, the communication medium bitrate can be better shared among users.



All data exchanged using IPv6 is contained in packets.

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Packets (cont.) 

The IPv6 packet is composed of : o

the fixed header

o

optional extension headers

o

the payload—the transport layer data carried by the packet



The control information provides data the network needs to deliver to the user data such as source and destination addresses.



The user data would be the information being sent.



An illustration of this concept is sending a letter in an envelope: o

The envelop has the address.

o

The user data is in the envelope.

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Unique Local Addresses (ULA) 

Included in Internet protocol IPv6.



The address block fc00::/7 has been reserved by IANA as described in RFC 4193.



Defined as unicast in character and contain a 40-bit random number in the routing prefix to prevent collisions when two private networks are interconnected.



Despite being inherently local in usage, the IPv6 address scope of unique local addresses is global.

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Private Network 

Private network is one scenario that uses a set of standards for private IP address space. o

Reserved address ranges are for local use.

o

Used for homes and small businesses

o

Also used in corporate networks not connected directly to the Internet for security



A NAT gateway is usually used to enable Internet connectivity to multiple hosts such as a second computer or a video game with IPv4.



IPv6 is designed so that network address translator (NAT) goes away.

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Private Network (cont.) 

Since IPv6 addresses are 128 bits long, the theoretical maximum address space if all addresses were used is 2128 addresses. o

This number, when fully expressed is 3.4*1038 or 340,282,366,920,938,463,463,374,607,431,768,211,456.

o

That's about 340 trillion, trillion, trillion addresses.

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Subnets 

To subnet an IPv6 global address prefix, either hexadecimal or decimal methods are used.



To subnet the IPv6 address space, use subnetting techniques to divide the 16-bit subnet ID field for a 48-bit global.



For global addresses, Internet Assigned Numbers Authority (IANA) or an ISP assigns an IPv6 address prefix in which the first 48 bits are fixed.



Subnetting the subnet ID field for a 48-bit global address prefix requires a two-step procedure: 1.

Determine the number of bits to be used for the subnetting

2.

Enumerate the new subnetted address prefixes

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Subnets (cont.) 

The number of bits used for subnetting determines the possible number of new subnetted address prefixes that can allocate portions of network based on geographical divisions.



Based on the number of bits used for subnetting, a list of the new subnetted address prefixes can be created with one of these approaches:



1.

Enumerate the new subnetted address prefixes by using hexadecimal representations of the subnet ID and increment.

2.

Enumerate the new subnetted address prefixes by using decimal representations of the subnet ID and increment.

Both methods produce an enumerated list of subnetted address prefixes.

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Subnet Mask 

A network address plus the bits reserved for identifying the subnetwork



The bits for the network address are all set to 1. o

Example: 11111111.11111111.11110000.00000000.



Called a mask because it can be used to identify the subnet to which an IP address belongs by performing a bitwise AND operation on the mask and the IP address



An IPv6 subnet mask is written in hexadecimal.



A full IPv6 subnet mask uses the same 8-hex-word format as an IPv6 address.



Like IPv4, an IPv6 address has a network portion and a device portion.



Unlike IPv4, an IPv6 address has a dedicated subnetting portion.

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Why Use IPv6? 

IPv6 has a vastly larger address space than IPv4. o



Results from a 128-bit address (IPv4 uses only 32 bits)

Other benefits of IPv6: o

Stateless address autoconfiguration

o

Multicast and mobility

o

Mandatory network layer security

o

Simplified processing by routers

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Lesson Review

Complete Student Activity 3.3_B

L EE SS SS O ON N L

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98-366 98-366Networking NetworkingFundamentals Fundamentals

Understand Names Resolution

LESSON

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98-366 Networking Fundamentals

Lesson Overview In this lesson, you will learn about:  Domain name resolution 

Name resolution process steps



DNS



WINS

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1.1

98-366 Networking Fundamentals

Anticipatory Set 1.

List the host name of 4 of your favorite websites, such as www.microsoft.com.

2.

Visit http://www.hcidata.info/host2ip.htm

3.

Enter the host names, one at a time, and click on the “Find IP Address” button.

4.

Record the IP address for each site.

5.

Describe the process of how the computer finds the IP address from a host name.

6.

Describe the process of how the computer finds a host name from an IP address.

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Name resolution 





IP address o

Identifies a computer on a network by a unique address

o

A string of four numbers separated by periods is the form of the address (for example, 192.168.1.42)

Domain name o

Used because people remember words better than numbers (for example, www.microsoft.com)

o

The name has to be assigned to a corresponding IP address to access a domain name.

A nameserver is a server that implements a name-service protocol, which maps an identifier to a system-internal, numeric addressing component.

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How WINS Works By default, when a system is configured to use WINS for its name resolution, it adheres to h-node for name registration. 1.

Checks to see if it is the local machine name

2.

Checks its cache of remote names. Any name that is resolved is placed in a cache where it remains for 10 minutes.

3.

Tries the WINS Server

4.

Tries broadcasting

5.

Checks the LMHOSTS file to determine if the system is configured to use the LMHOSTS file

6.

Tries the HOSTS file and then a DNS, if so configured

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Domain Name System (DNS) 

The Internet maintains two principal namespaces, the domain name hierarchy and the Internet protocol (IP) address system.



The domain name system maintains the domain namespace and translates between these two namespaces.



Internet name servers implement the domain name system.



A DNS name server is a server that stores the DNS records, such as address (A) records, name server (NS) records, and mail exchanger (MX) records for a domain name.

LESSON

1.1

98-366 Networking Fundamentals 

Resolvers are programs that run on DNS clients and DNS servers and that create queries to extract information from name servers.



Domains define different levels of authority in a hierarchical structure. The top is called the root domain. The DNS namespace on the Internet has the following structure:  The root domain uses a null label, which you write as a single period (.) and is assigned by organization type and by country/region.  Second-level domain contains the domains and names for organizations and countries/regions.  A zone is a contiguous portion of a domain of the DNS namespace whose database records exist and are managed in a particular DNS database file stored on one or multiple DNS servers.

LESSON

1.1

98-366 Networking Fundamentals 

DNS defines two types of name servers:  A primary name server gets the data from locally stored and maintained files. To change a zone, such as adding subdomains or resource records, you change the zone file at the primary name server.

 A secondary name server gets the data across the network from another name server. 

The process of obtaining this zone information (that is, the database file) across the network is referred to as a zone transfer.

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Host Name Resolution Process Resolves a host name to an IP address before the source host sends the initial IP packet The default order for domain name resolution 1.

2.

3.

Hosts File—There is a file called HOSTS to convert domain names to IP addresses and entries in the HOSTS file dominate mappings that are resolved via a DNS server. Domain Name System —Used for converting domain names to their corresponding IP addresses. The operating system will connect to the DNS server and return to you the IP address for the domain name you queried it with. Netbios—This only applies to Windows machines and will only be used to map names to IP addresses if all previous methods failed. Windows tries NetBIOS name resolution first, then host name resolution.

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NetBIOS over TCP/IP Name Resolution



b-node—broadcasts are used for both name registration and name resolution.



p-node—uses point-to-point communications with a name server to resolve names.



m-node—first uses b-node and then, if necessary, p-node to resolve names.



h-node—first uses p-node for name queries and then b-node if the name service is unavailable or if the name is not registered in the database.

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Reverse Lookup of the DNS Namespace •

•

Within the in-addr.arpa domain, special pointer (PTR) resource records are added to associate the IPv4 addresses to their corresponding host names. To find a host name for the IPv4 address 157.54.200.2, a DNS client sends a DNS query for a PTR record for the name 2.200.54.157.in-addr.arpa.

LESSON

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98-366 Networking Fundamentals 

All the Methods Used by TCP/IP for Windows XP and Windows Server 2003 for Resolving Host Names

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98-366 Networking Fundamentals 

DNS name resolution is both iterative and recursive resolution. 1.

The user types in a DNS name into a Web browser, which causes a DNS resolution request to be made from her client machine’s resolver to a local DNS name server.

2.

That name server agrees to resolve the name recursively on behalf of the resolver, but uses iterative requests to accomplish it.

3.

These requests are sent to a DNS root name server, followed in turn by the name servers for “.edu”, “someschool.edu”, and “compsci.someschool.edu”.

4.

The IP address is passed to the local name server and back to the user’s resolver and finally, her Web browser software.

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98-366 Networking Fundamentals

Lesson Review Complete Student Activity NetFund_SA_3.4

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Understand Networking Services

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98-366 Networking Fundamentals

Lesson Overview In this lesson, you will learn about: 

Networking services



DHCP



IPsec



Remote access

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98-366 Networking Fundamentals

Anticipatory Set Most schools use DHCP to manage student access to networks. 

What happens when you log on?



List all of the services a computer network provides when using DHCP.



What IP address do you start with?

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98-366 Networking Fundamentals

Network Services 

Installed on one server to provide secure shared resources to clients



Common network services include: o

Authentication servers—the process by which the system validates a user’s logon information

o

Directory services—a service on a network that returns mail addresses of other users or enables a user to locate hosts and services

o

DNS—naming system for computers, services, or any resource connected to the Internet or a private network

o

Network file system—distributed file system accessed over a network

o

E-mail

o

Printing

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98-366 Networking Fundamentals

DHCP—Dynamic Host Configuration Protocol 

An autoconfiguration protocol used on IP networks



Provides a central way to configure the network settings of all of your networked computers



If your operating system is configured to use DHCP, users just need to plug in the network cable and are ready to go.



DHCP can configure: o



IP address, network mask, DNS address, WINS server address, host name, domain name, gateway address, time server address, print server address

Keeps track of computers connected to the network and prevents two computers from being configured with the same IP address

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98-366 Networking Fundamentals

Methods of Allocating IP Addresses 

Dynamic—requires use of DHCP



APIPA—automatically assigns an address as a last resort



Static—manually assigns an address by an administrator



DHCP operations fall into four basic phases: o

IP discovery

o

IP lease offer

o

IP request

o

IP lease acknowledgement

LESSON

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98-366 Networking Fundamentals 

Where a DHCP client and server are on the same subnet, communication is processed through UDP broadcasts.



Where the client and server are on different subnets, IP discovery and IP request messages are sent via UDP broadcasts and IP lease offer and IP lease acknowledgement messages are sent via unicast.

Process: 1.

A DHCP-configured client connects to a network and sends a broadcast query requesting information from a DHCP server.

2.

If the request is valid, the server assigns the client an IP address, a lease (length of time the allocation is valid), and other IP configuration parameters, such as the subnet mask and default gateway.

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98-366 Networking Fundamentals

Remote Access 

Communication with a data processing facility from a remote location through a data link



Allows you to extend a network beyond the physical boundaries of the wired network



Available with three models: hosting service, software, and appliance

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98-366 Networking Fundamentals

Remote Access Server 

Sometimes called a communication server; is set up to handle users seeking access to network remotely



Associated with a firewall server to ensure security and a router that can forward requests



In transport mode, only the payload (the data you transfer) of the packet is encrypted and/or authenticated



The transport and application layers are always secured by hash, so they cannot be modified in any way.

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98-366 Networking Fundamentals

Internet Protocol Security (IPsec) 

A protocol suite for securing Internet protocol (IP) communications by authenticating and encrypting each IP packet of a data stream



Includes protocols for establishing mutual authentication between agents at the beginning of the session and negotiation of cryptographic keys to be used during the session



Protects data flows between a pair of hosts (computer users or servers), between a pair of security gateways (routers or firewalls), or between a security gateway and a host

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98-366 Networking Fundamentals

IPsec (continued) 

IPsec can be used for protecting any application traffic across the Internet and is a framework of open standards.



Authentication header (AH) provides connectionless integrity and data origin authentication for IP datagrams and provides protection against replay attacks.



Encapsulating security payload (ESP) is a member of the IPsec protocol suite and provides origin authenticity, integrity, and confidentiality protection of packets.

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98-366 Networking Fundamentals

Lesson Review Student Activity NetFund_SA_3.5

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98-366 98-366Networking NetworkingFundamentals Fundamentals

Understand TCP/IP

LESSON

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98-366 Networking Fundamentals

Lesson Overview In this lesson, you will learn about: TCP/IP

Ping

Tracert

Pathping

Telnet

Ipconfig

Netstat

Protocols

Reserved addresses Local loopback IP

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98-366 Networking Fundamentals

Anticipatory Set Experiment with ping and tracert. 1.

From the start menu, go to the Run (Win XP) or Search (Win7) command and type cmd. This brings up a DOS command window.

2.

Type ping www.microsoft.com

3.

Ping a few of your favorite sites (www.facebook.com, www.bing.com, www.wikipedia.org , etc.).

4.

Now ping a few geographically close websites (local government, local TV station, local university, etc.).

5.

Record the average times to see which "roundtrips" are the fastest.

6.

Now experiment with tracert using the same urls.

7.

Summarize the results.

8.

Summarize your understanding of ping and tracert.

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98-366 Networking Fundamentals

Internet Protocol Suite 

Two original components o

TCP – Transmission Control Protocol

o

IP – Internet Protocol



TCP operates at a higher level, concerned only with the two end systems such as the Web browser and a Web server.



IP handles lower-level transmissions from computer to computer as a message makes its way across the Internet.

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98-366 Networking Fundamentals

TCP 

Provides a communication service between an application and the IP



Provides reliable, ordered delivery of a stream of bytes from a program on one computer to another program on another computer



Controls segment size, flow control, data exchange rate



Keeps track of the individual units of data transmission, called segments, that a message is divided into for routing through the network



Applications include e-mail and file transfer, and the Web.

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98-366 Networking Fundamentals

IP 

Handles the actual delivery of the data



Works by exchanging pieces of information called packets



For example, when an HTML file is sent from a Web server, the TCP software layer of that server divides the sequence of bytes of the file into segments and forwards them individually to the IP software layer (Internet Layer).



The Internet layer encapsulates each TCP segment into an IP packet by adding a header that includes (among other data) the destination IP address.

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98-366 Networking Fundamentals

IP Packets 



A sequence of bytes consisting of a header and a body o

The header describes the packet's destination and the routers to use for forwarding until it arrives at the final destination.

o

The body contains the data IP it is transmitting.

IP packets can be lost, duplicated, or delivered out of order. o



TCP detects these problems, requests retransmission of lost packets, rearranges out-of-order packets, and helps minimize network congestion.

Individual packets of the same message can be routed on different paths through the network.

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98-366 Networking Fundamentals

TCP/IP Stack 

The TCP or UDP transport layer 4 sends packets to IP network layer 3, which adds its own header and delivers a "datagram" to a data link layer 2 protocol.



TCP/IP tools are in layers 7, 6, 5.

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98-366 Networking Fundamentals

Port Numbers 

TCP uses port numbers to identify sending and receiving application end-points on a host.



Three basic categories: well-known, registered, and dynamic/private



Some examples include FTP (21), SSH (22), TELNET (23), SMTP (25) and HTTP (80).

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98-366 Networking Fundamentals

TCP/IP Tools Ping: Tests if a particular host is reachable across an IP network; measures the round-trip time for packets sent from the local host

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98-366 Networking Fundamentals

TCP/IP Tools Netstat: Displays current TCP/IP network connections and protocol statistics

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98-366 Networking Fundamentals

TCP/IP Tools Tracert: Shows the route taken by packets across an IP network

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98-366 Networking Fundamentals

TCP/IP Tools Ipconfig: Displays all TCP/IP network configuration values and refreshes DHCP and DNS settings /? Command will play all options available with ipconfig

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98-366 Networking Fundamentals

TCP/IP Tools Pathping: Displays the degree of packet loss along the path

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98-366 Networking Fundamentals

TCP/IP Tools 

Telnet: A terminal emulation program for TCP/IP networks



Local loopback IP: Tests the TCP/IP protocol implementation on a host -special range of addresses (127.0.0.0 to 127.255.255.255) is set aside



Localhost: Translates to the loopback IP address 127.0.0.1 in IPv4 or ::1 in IPv6

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98-366 Networking Fundamentals

Lesson Review Student Activity NetFund_SA_3.6